2^N Internal combustion engine

I am sorry to disappoint you since almost all your ideas are already in use!

There are engine working with variable number of cylinders already, this is obtained by opening a given number of cylinders to the atmosphere in order to reduce power losses due to compression.

The turbocharger is a turbine actuated by exhaust gases and used to compress air for inlet, heating of input air is also used but not always all this complexity is related to COST and the engine becomes a LOT more expensive so that only some cars of the upper class are concerned.

The high pressure cannot be too high because of mechanical limitations and inertia of pistons and connecting rods being of higher mass.

I do not want to be misunderstood may be some ideas are good but before you go further considering that engine specialists are less clever than electronicians without a basic knowledge of thermodynamics,mechanics and combustion it would be good to go deeper in what is already available or even used.

Thanks a lot for very valuable comments.

In electronics we have digital to analog convertor where we have binary numbers zeros and ones. But the weightage given to each zero and one depends on its position. Hence using a simple 3 bit binary we can get 8 combinations.

Given this let us say one cylinder has volume 25 cc, second one will be 50 cc, third 100 cc. During idling only say 25 cc operates. for speeds below 10km/hr say 50 cc alone operates. 11 to 20 km/ hr 25 + 50 cc operate. 21 to 35 km/hr say only 100 cc operates, then for 36 kms /hr to 60 km/hr, 100 +25 cc operate and so on . We can make combinations so that for full power all three will be operating. Since all are on teh same shaft, stroke length remaining the same, dia can be varied. This discussion can be carried forward depending on enthusiasm generated.

In this manner we have programmed PV curves, thus improving effeciency.

Please think about how an engine will work with only 1 cylinder. It will generate tremendous vibrations and bad feeling for the users. This is the reason why yhe mentioned engine works with either 3 or 6 cylinders. As in an electric motor an engine works with a rotating torque vector. How will work a 3 phase motor with only 1 phase or 2? As electronician you are aware of the problems. Universal motors or single phase motors need a help to generate the rotating vector (capacitance, aso). The engine will need a huge inertia to accumulate energy during the active part of cycle and allow it to supply the car during the inactive periods.

There is an other thermodynamic factor. You mention same stroke and different diameters. One important parameter is the ratio surface / volume since the bigger it is the more energy is lost via transfer to environment so the lower the efficiency. If you write mathematically the ratio it is A/V=π*d*s/(π/4*d²*s)= 4/d so that the smaller the diameter the higher the ratio and the lower the efficiency. If you look at the engines the ration is such that the volume is as far as possible near to a sphere. There is also an other reason in order to have a good flow of air and gas the valves have to be as big as possible. The smaller the diameter is the less place for the valves. By the way you need in your idea also 3 types of valves and most probable different cam profiles and different advances an optima tuning for every cylinder so that also 3 controllers. And I do not list all problems.

It is already a problem to assure a good maintenance for engines where all pistons are identical, please imagine what will be the problems (logistics and cost) for a solution with 3 pistons all of them different!

You make a comparison with ADC and DAC in electronics, but they consist in ladders of identical resistors (some of them) and switches. As principle I do not contest the possibility but it is not possible to transfer a principle valid in a technology into an other. There are a LOT of technology related constrains which limit the "idea" transfer.

I am sure you will invest -as every inventor does- a lot of energy and money in this idea despise of all warnings, if you want to continue try first to understand the problems from the mechanical side since you want to make a mechanical device before you go too deep.

This is not just turning off cylinders. This is about different compression ratio's for different stages of engine load. I don't think I've ever heard of anyone trying anything like that.

Dear Sir,

A few years ago I was approached by an Australian Mechanical Engineer/Inventor. His concept was that you could electronically modify (during engine operation ) the lenght of the piston arm so as to approach, to some extent , what you are : now suggesting.

Though I am not a mechanical engineer varying at will the combustion chamber or modifying /increasing the velocity of exhaust gases have both great potential which your knowledgeable conclusions appear to represent. I am certain better equipped contributors will " give you a run for your money " and help you in your search.

Good Luck

Labor Omnia Vincit.

Scuderi Air Hybrid Engine

Variable cylinder use

I think you are right. Honda's approach seems to be very close to what I have been suggesting.

Having accepted the concept of cylinders with different volumes and programmed to operate in a particular manner - I had put forth the idea of of further splitting the cylinder into two - where fuel suction & compression are handled in one compartment + ignition and exhaust are handled in another compartment. This can also provide turbo or super charge effect- which improves the efficiency further.

"Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great." -- Mark Twain

Has been already done but I do not know results.

" I had put forth the idea of of further splitting the cylinder into two - where fuel suction & compression are handled in one compartment + ignition and exhaust are handled in another compartment. This can also provide turbo or super charge effect- which improves the efficiency further."

Did you also look at the link I posted to the Scuderi Engine? It does just this.

The problem I think you would have with size differentiation is one of economy. It becomes increasingly expensive to produce an engine with so many different components where as with multiple cylinders of which some are selectively enabled, you have a cleaner design. Also there are matters of balance and symmetry that are kept simple.

Hello Guys,

Maybe it's high time to bring back the Wankel Engine and tweak it so with improved technological advances of the past 30 years, especially electronics?????

Never did understand why Mazda put the engine to bed in the first place and didn't refine it any further.....

re wankel engine.

it is still in use on some mazda`s.

it has very poor mpg.

and is heavy, and the rotor tips burn out very fast, and keeping rotor gas tight is an issue.

i worked on early wankel as fitted to the nsu ro80.

the engine was very very heavy for a two cylinder engine.

power output was very smooth though.

air intake noise was an issue, and igniton system used a very high amp spark system using two spark plugs which burnt out very quickly.

i think all the problems they had caused the death of engine

A digital IC engine. What a concept. I want to really look at your design. It does look expensive though.

I hope you have gone through the entire thread of discussions. Yes for an electronic engineer like me IC normally means integrated circuit. But I had posed a question in automotive segment and had to make it clear that I was talking about internal combustion engineering.

Instead of this mode of communication, if you give your email ID- I can send you a word document with more details of what I have in mind. Do also let me know your background / interests.

Tweeking Wankel engine using electronics - is food for thought now!! Basically I am an electronic engineer and am looking forward to a good automobile / IC engine expert to team up. One has to work in a multi-disciplined environment now - further involving metallurgists, chemical engineers also I suppose.

t certainly is challenging & exciting too.

I've seen something like this before, I will see if I can find it. You have a pre-compression chamber it looks like. Have you thought about using diesel? Diesel is prefect for a high compression system. That would also get rid of your spark plug. You would have to watch how high the compression gets in the first chamber. You wouldn't want the first chamber firing, or would you???? Hmmm

Why did I start with 2 chamber philiosophy? -

1. The exhaust and incoming fuel do not get mixed at any time. The reason for inefficiency in current 4 stroke engne is - fuel is not fully burnt and some quantity of input fuel may get scavenged out to exhaust 9ratio depnds on engine speed I suppose).

2. You can draw in a specified amount of fuel and for burning you can have a second chamber which is smaller and already that means higher compression.

3. You are right- it could be diesel too!! Basically we are trying to see how to improve internal combustion engine.

4.PV curve is constant. Vehicles are supposed to be efficient only between about 40 and 60 kms/hr - as marked in many vehicles on teh speedometer. Can we stretch this limit and keep the system efficient over entire range- from idling to full power if possible.

5, Current 4 stroke engine designs are by people- from mecahnical engineering and automotive background- who then brought in electronic engineers to add MPFI etc etc. Now I am an electronic engineer pushing automotive engineers to have a rellok at their concept !! After all it is team work.

So these were basic objectives I had set out to begin with.

"It doesn't matter who you are, where you come from. The ability to triumph begins with you. Always." -- Oprah Winfrey